Medical student Leana Wen knows becoming a doctor means that she will soon get lots of nice gift offers--catered lunches, dinners at fine restaurants and endless office supplies, to name a few--from drugmakers that hope she will readily prescribe their products. Yet rather than relish these traditional perks, Wen and the 60,000-member American Medical Students Association (AMSA) have launched a campaign to offset the influence of drug-industry representatives. Students at 150 medical schools intend to fan out this year across the country, calling on 40,000 doctors, urging them to stop depending on salespeople bearing gifts. "Accepting gifts from drug companies influences...